hc256.h

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// hc256.h - written and placed in the public domain by Jeffrey Walton
//           based on public domain code by Hongjun Wu.
//
//           The reference materials and source files are available at
//           The eSTREAM Project, http://www.ecrypt.eu.org/stream/hc256.html.
 
 
#ifndef CRYPTOPP_HC256_H
#define CRYPTOPP_HC256_H
 
#include "strciphr.h"
#include "secblock.h"
 
NAMESPACE_BEGIN(CryptoPP)
 
 
struct HC256Info : public FixedKeyLength<32, SimpleKeyingInterface::UNIQUE_IV, 32>
{
        CRYPTOPP_STATIC_CONSTEXPR const char* StaticAlgorithmName() { return "HC-256"; }
};
 
class HC256Policy : public AdditiveCipherConcretePolicy<word32, 4>, public HC256Info
{
protected:
        void CipherSetKey(const NameValuePairs &params, const byte *key, size_t length);
        void OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount);
        void CipherResynchronize(byte *keystreamBuffer, const byte *iv, size_t length);
        bool CanOperateKeystream() const { return true; }
        bool CipherIsRandomAccess() const { return false; }
 
        word32 H1(word32 u);
        word32 H2(word32 u);
        word32 Generate();
 
private:
        FixedSizeSecBlock<word32, 8> m_key;
        FixedSizeSecBlock<word32, 8> m_iv;
        word32 m_P[1024];
        word32 m_Q[1024];
        word32 m_ctr;
};
 
struct HC256 : public HC256Info, public SymmetricCipherDocumentation
{
        typedef SymmetricCipherFinal<ConcretePolicyHolder<HC256Policy, AdditiveCipherTemplate<> >, HC256Info> Encryption;
        typedef Encryption Decryption;
};
 
NAMESPACE_END
 
#endif  // CRYPTOPP_HC256_H